fix: Fix projection pushdown with literal joins

[ritchie46]

fixes #11410

[codspeed-hq]

CodSpeed Performance Report

Merging #16981 will degrade performances by 17.56%

_{Comparing join (80179c8) with main (9e3e9b0)}

Summary

❌ 1 regressions
✅ 36 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	join	Change
❌	test_tpch_q3	5.4 ms	6.5 ms	-17.56%

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.03%. Comparing base (9a3e032) to head (80179c8).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16981      +/-   ##
==========================================
- Coverage   81.04%   81.03%   -0.01%     
==========================================
  Files        1445     1445              
  Lines      190301   190320      +19     
  Branches     2709     2709              
==========================================
+ Hits       154224   154232       +8     
- Misses      35579    35591      +12     
+ Partials      498      497       -1     

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[mcrumiller]

@ritchie46 related #9621, why does the join result in a literal column at all? If on clauses are intended to generate columns, we should be able to alias them, but we can't.